


How Love Corrupts

by DeathPunkin



Category: Undertale (Video Game)
Genre: Consent is not explicitly given, Darkfic, Dom Papyrus, Incest, M/M, Papyrus Has Issues, Papyrus is the one with only one glowing eye, Sans Has Issues, Sans enjoys this, Sans has issues sleeping, Sub Sans, Underfell AU, pleasant dreams are nightmares, skeletons banging, well more of a lazy bottom
Language: English
Status: Completed
Published: 2015-12-23
Updated: 2015-12-23
Packaged: 2018-05-08 17:11:59
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 1,227
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5506100
Author URL: https://archiveofourown.org/users/DeathPunkin/pseuds/DeathPunkin
Summary: <blockquote class="userstuff">
              <p>Underfell Sans and Papyrus incest bang, and like it.</p>
            </blockquote>





	How Love Corrupts

**Author's Note:**

> So this came from an idea. This is the ship I have found out of all of the alternate universes and the cannon one too to have incest sex on a regular basis. The thing is my twin loves incest (not between us, she just ships it a lot) so I thought why not? That's how this came to be. Also, I was thinking of writing a fic where the AU is an asylum one. What do you guys think? What should I name it? The fic and the AU, Underdrugs? Also, there should be another story out soon that is a cross over and is between Mettatons. I may not add smut though. Tell me what you think in the comments below!

It's no secret that Sans has ridiculously good dreams. He always wakes up from them either screaming or falling, and sometimes he even throws up because of that. Thankfully the outer walls of their house are sound proof. In this world... it's kill or be killed. Papyrus just so happens to not like working the Gaster Blasters alone, really. That's all there is to it.  
Still, tonight is another in the never ending stream of hopes and dreams that keep invading his brother's mind. This is it, the final night he will take it. He'd even warned his brother, and now the yelping skeleton is going to have a bad time. He had even shared his glorious monster truck bed, and that still isn't helping. Screen helping. Papyrus wakes up Sans by shoving his small body against one of his walls.

  
Sans jolts awake from the sensation of a hand pressing against his neck. Before he can process anything, he it caught upon a hot and messy kiss from his brother. He can feel that delicious lounge plunge deep into his mouth, and it maps out every part of his mouth. Sans can't help but moan at the rough treatment. He should have figured that the tab would be settled by the use of his body.

  
After all, that does seem to be his preferred method of getting repaid, especially when it comes to Sans. The shorter skeleton manages to break away for a moment. He rubs at the area he knows will form, right between Papyrus's legs and hips. He is not disappointed when he hears his brother's voice. "Pull them off," just to annoy him, Sans begins to take them off with his hands. Papyrus growls at him in response. "Not with those, use your mouth," he orders and Sans sighs before following the order, and playfully tugging the pajama pants off of his brother.  
As the pants make the rest of their way to the floor, Sans can't help but to playfully bite Papyrus's legs. Papyrus can't help but to sigh at the sensation. He then slowly bites his way up to what is an obvious erogenous zone on any skeleton; the pelvis. He nibbles at the the joint between the pelvic bone and Papyrus's left leg. Sans has to move so as not to be hit by Papyrus's knee which often jerks up slightly at over stimulation, and something else entirely. In the darkness of their room, Sans can now see the red glow of his brother's sudden boner. Sans grins to himself.

  
Skeleton boners are different from normal dicks in a few ways. 1. They are made entirely of magic, well duh what else would they be made out of? 2. They only appear when a skeleton is aroused enough to be leaking or close to it. Total check here. 3. They look like the area leading up to a shoulder joint, well of course. That's one of the most phallic parts of a skeleton. 4. There is nothing harder than a sekleton's dick. And finally, number 5. Sans likes Skeleton dicks more than any other kind. Especially his brother's.  
He starts to suck on it like a lollipop. He teasingly traces the head with his long red tongue before plunging as much as he can fit of it into his mouth. He moans to help by sending vibrations up and down Papyrus's boner. Sans suddenly feels a shove on his shoulder. "You seem to be enjoying this a bit too much, brother. Come up onto my lap, but minus the clothes," he orders, and Sans is forced to obey. Well, perhaps 'forced' is the wrong word. Sans is more than willing to climb into Papyrus's lap, regardless of the connotation.  
So he climbs pantsless into his brother's lap. All he has left in is his signature burgundy jacket as Papyrus had already ordered him a while ago to not wear his shirt around their house. He shivers as he feels bony hands ghost across his ribs. Soon harsh bites accompany the smooth caresses, bringing Sans the rest of the way and with a tug and a gasp, he can feel his own skeletal erection spring into being.

  
Sans looks up to find the smirking face of his younger brother. "Enjoying yourself?" He asks, and Sans realizes that he had accidentally been rutting against Papyrus's rather satisfying boner. Sans blushes a bit, but tries to make it look more like the action was on purpose.  
Sans let's out a playful moan, as he rubs harder. He doesn't use his hands as those are firmly attached to Papyrus's spiky shoulder pads. "Mmmmmm, yes," Sans moans some more. Surely this will keep up the charade.

  
It fails miserably. "I know that wasn't intentional. Do you remember Sans? In this world you can't show any weakness. You have just shown me the weakness of your pleasure, and I just have to take advantage of that," he says all of this while idly stroking Sans. The strokes are light, as though barely interested, but below tells another story. Still, Sans can't help but to moan quietly at the soft touches. "Don't you remember Sans? In this world, it's kill, or be killed," he concludes darkly before firmly placing two hands on Sans's hips and violently turning him around.  
Papyrus holds up his brother with one arm as he positions his still wet dick at Sans's entrance. It is a small space that forms between the dick and the pelvis and is only created for events like these, and since Sans has only done this with Papyrus, it has only formed for him. Papyrus just shivers his dick into the small opening. He can hear sans moaning from his place on his lap due to the sudden penetration. Papyrus gives Sans a few moments to enjoy that or something, before he begins pounding into the body he has above him.

  
He holds Sans still by wrapping his arms around his older brother's chest, and twinning his hands in between Sans's ribs, much like the vines of a nightmare. He pounds into the shorter skeleton, but that doesn't entertain him for long. So he flips them around and onto his bed. He begins bounding into that tight hole raised specifically for him.

  
The sight of that submission that he rarely sees anywhere else is what finally drags him over the edge. Papyrus gives a few last, hats thrusts before spilling his magic into Sans. Sans can hardly hold himself back at the delightfully wet feeling of being filled. He speed his load all over the bed. He's just thankful that as soon as the magic stops, all of this will be over. He tries to wiggle out of his brother's embrace, but Sans finds that he can't. He growls at that fact. "Sans, I'm stuck inside of you," Papyrus whispers in his ear. Sans wants to get frustrated at him, but he knows for a scientific fact that notting is rather common among skeletons. Still, that makes this no easier. "That means you're all mine for a little while longer," Papyrus growls above him, and Sans can't help but to shudder. In the end, no matter what was done or said, a the two fell asleep like that on that particular night and no one can deny it.


End file.
